On a motion by Chico Supervisor Maureen Kirk, the board unanimously voted to limit marijuana gardens not by the number of plants but by square-footage.

Where the property is greater than a half-acre but less than five acres, the garden can be no larger than 50 square feet. On a parcel greater than five acres but less than 10, the garden must be no larger than 100 square feet. On land over 10 acres — no matter how much larger — the maximum garden size is 150 square feet.

Under the approved amendment, the garden must fit within an imaginary "glass box" and all the foliage must be entirely within the square-foot limitation.

A sheriff's official "guesstimated" the 50-square-foot garden could hold two reasonably large plants that between them could produce up to 10 pounds of usable cannabis a year. The 100-square-foot garden could hold four plants and the 150-square-foot operation could hold six reasonably large plants.

As part of Kirk's proposal, the gardens have to be set back 50 feet for the smallest garden, 75 feet for the five-to-10-acre parcel and 150 feet for the largest growing sites.

Kirk's proposal came after nearly three hours of testimony during which all but a handful of individuals urged the board to tighten restrictions on growers.

Kirk said she wanted to make it clear, "We do care about families, we do care about crime, we do care about the environment."

Chico Supervisor Larry Wahl, who has long been the most ardent advocate for tight medical marijuana restrictions, said he wanted to see specific limits on the number of plants in each of the "glass boxes," but other members of the board said cramming more plants on the tiny plots will not increase the amount of usable marijuana.

Oroville Supervisor Bill Connelly described the proposal as "very restrictive."

Kirk added an additional amendment that would eliminate the restriction on who can complain about a medical marijuana garden. The existing ordinance required in the vast majority of cases that the complaining party live within 1,500 feet of the property line of the parcel where the garden is located.

"Let anyone complain. I think we found 1,500 feet was too restrictive" on the public, said Kirk.

Both the people in favor of the tighter restrictions and those opposed made it clear the law is likely to face a referendum.

Andrew Merkel, a long-standing marijuana advocate and a member of the citizens' committee that helped craft the existing cultivation amendment, spoke in the public testimony segment and said it was clear to him the new proposal was going back before the people in a vote.

Last week, he said marijuana advocates had begun the process to get another measure before the public.

During the discussion over whether or not to restrict the number of plants, Connelly said, "It doesn't matter. We are going to go to an initiative whatever we do."

The ordinance amendments will come back before the board Jan. 28. If they pass that hurdle, it will come up for a final vote at the Feb. 11 meeting, which will be almost exactly one year after the existing ordinance was passed.